Identification Of Cold Tolerance Of Main Indica Rice Varieties In Yanbian Area

The experiment was carried out in the Yanbian Korean Autonomous Prefecture Academy of Agricultural Sciences from 2017 to 2018.The new high-quality japonica rice varieties in Jilin Province were used as test materials,and the low temperature stress treatment was carried out in the germination stage,seedling stage,tillering stage,meiosis stage and filling stage.The internal light intensity of the artificial climate chamber simulates the natural and rainy conditions for 12h,and the rice under the greenhouse condition is used as the control.The germination rate,seedling rate,physiological characteristics,yield and composition factors of rice under different temperature stress in different periods are compared.The research on the impact of quality provides a scientific basis for the prevention of rice cold damage in Yanbian area and the selection of high-yield and high-quality varieties.1.Screened out Longdao 18 with strong cold tolerance during germination;Jiudao 68 and Jijing 511 with strong cold tolerance;and Tongyu 266 for cold tolerance.There are Shangyu 397 and Jijing 809 which are strong in cold tolerance during the germination stage;Longdao 18,Jijing 302,Tonghe 66,Jijing 511,Yanjing 22 and Jiyuyu are among the cold tolerance.The plant height and chlorophyll content were significantly affected by low temperature stress in the tillering stage.The effects of Longdao 17,Longdao 18,Jinongda 538 and Shangyu 397 were relatively small.Jiudao 68,Jiyujing and Jijing 511 The chlorophyll content of Jinongda 538 is relatively small.The changes of protective enzymes in leaves of different cultivars under different low temperature stresses were significant.Under different low temperature stress,the enzyme activities were 7℃>5℃>3℃,Longdao 18,Jijing 809 and Jiudao 68.The enzyme activity of Jiyujing was stronger at the seedling stage;the activity and growth of Tongxi 935,Tongyu 266 and Jijing 511 were stronger after the low temperature stress in the tillering stage;the meiosis was affected by low temperature stress.The activity and growth rate of 809 were stronger.The activity and growth of Jijing 511 and Tongyu 266 were stronger after the low temperature stress.The activities of SOD,CAT and POD in leaves of different time were significantly increased under low temperature stress.The activities of SOD and POD were significantly changed,and the activity of CAT was stable.3.In the different periods of low temperature stress,the yield of rice was reduced.From the perspective of yield components,the number of panicles,the number of panicles,the seed setting rate and the thousand weight were all affected.The varieties that are less affected by delayed chilling injury yield are Longdao 17,Tong 35 and Jijing 511.The varieties that are less affected by the production of barrier-type chilling damage are Tong 35,Tongyu 266 and Jijing 809.The effects of low temperature stress on the milled rice rate and amylose content were small in different varieties and different periods.The low temperature stress on the grain filling stage had a great influence on the white grain rate and the white grain rate of rice.Small,in which Shangyu 397,Yanjing 22,Tong 35 white grain rate,high whiteness content,poor appearance quality;meiosis period after low temperature stress,grain filling mature protein content increased,The low content of Nongda 538,Tongxi 935,Jiyjing 511,Jiyjing 515,Tongyu 266 and Jiyjing 809 is relatively stable and the nutritional quality is good.